The present invention relates to hermetic refrigerant compressors, and more particularly to the application of thermoelectric devices in a compressor.
In general, a hermetic compressor may be part of a refrigeration, heat pump, or air conditioning system including a condenser, expansion device, and evaporator. The compressor includes a housing in which a motor and compression mechanism are mounted. The motor and compression mechanism are operatively coupled by a drive shaft which is driven by the motor to operate the compression mechanism. Suction pressure gas received from the refrigeration system is drawn into the compression mechanism and is compressed to a higher, discharge pressure before being returned to the refrigeration system.
The high pressure discharge gas exiting the compressor enters the condenser where it is cooled and condensed to a liquid. The high pressure liquid passes through an expansion device which reduces the pressure of the refrigerant. The low temperature refrigerant liquid then enters the evaporator. During the evaporation process, heat is transferred from the area being cooled, such as a refrigerator or building, to the liquid in the evaporator, the temperature of which increases and returns to a vapor or gas. The low pressure suction gas enters the compressor from the evaporator and is again compressed.
Heat present in the compressor can have an adverse effect on the efficiency of the compressor, particularly heat transferred to suction pressure gas flowing toward the compression mechanism. If the temperature of the suction pressure gas is too high, the efficiency of the compressor may be reduced. It is therefore desirable to remove heat from the suction pressure gas to improve compressor efficiency.
Thermoelectric devices are well known in the art as being used to remove heat from a surface on which the device is mounted. In one previous application disclosed in U.S. Pat. No. 5,180,293 to Hartl, a plurality of thermoelectric elements are mounted to opposite sides of a heat exchanger. A heat sink is mounted to the thermoelectric elements to dissipate heat pulled from the heat exchanger, and fluid in the heat exchanger, by the thermoelectric elements prior to the fluid being pumped.
A problem with cooling the suction pressure gas at the heat exchanger prior to pumping is that the heat in the thermoelectric device must be dissipated which may require fins, for example, being mounted to the heat exchanger, thus increasing the size and amount of space required by the refrigeration system. The thermoelectric elements are also mounted to an external surface of the heat exchanger which also increases the amount of space occupied thereby.
It is desired that the present invention provide a thermoelectric device for removing heat from the suction pressure gas once the gas has entered the compressor to improve efficiency of the compressor while not increasing the amount of space required by the refrigeration system.